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M M Freitas

Publications and source records attributed to M M Freitas.

3 recordsLinked to original sources
PubMed1994

[The Program of External Quality Evaluation in Clinical Chemistry. An overview and evaluation after 11 years of functioning].

After an eleven-year period, the goals and way of functioning are remembered the External Quality Assessment Scheme in Clinical Chemistry, under the responsibility of the National Institute of Health. The authors try to evaluate the quality of results obtained at the time by the 160 participant laboratories, belonging to the public and private sectors as well as to the Portuguese reference laboratories which have to assign the expected values on the control sera to be analysed. As regards the 22 biochemical blood parameters, we came to the conclusion that there is a high performance level in what concerns the reference laboratories and a quality level of participant laboratories in accordance with their considered peer foreign laboratories.

Chemistry, Clinical↗
PubMedDate not supplied

Two methods for recommending bat weights.

Baseball players swung very light and very heavy bats through our instrument and the speed of the bat was recorded. These data were used to make mathematical models for each person. Then these models were coupled with equations of physics for bat-ball collisions to compute the Ideal Bat Weight for each individual. However, these calculations required the use of a sophisticated instrument that is not conveniently available to most people. So, we tried to find items in our database that correlated with Ideal Bat Weight. However, because many cells in the database were empty, we could not use traditional statistical techniques or even neural networks. Therefore, three new methods were used to estimate the missing data: (i) a neural network was trained using subjects that had no empty cells, then that neural network was used to predict the missing data, (ii) the data patching facility of a commercial software package was used, and (iii) the empty cells were filled with random numbers. Then, using these fully populated databases, several simple models were derived for recommending bat weights.

Adolescent↗